Lawyer explains your legal right to leave work if it's too hot

Scorching heatwave conditions have returned to the UK in earnest and it's set to get even hotter - but how hot does it legally have to be before you can stop working? Parts of the UK are set to bake in 33C conditions on Tuesday, while temperatures thereafter will remain high.

The Met Office is predicting 33C in London on Tuesday, followed by two days at 29C and then 30C again on Friday. And after another sticky and warm day across the country, and even more heat coming, many people are beginning to ask how hot it has to be before you can legally stop working. In some countries, there is a legal limit defined in Celsius. For example, in Qatar, workers on buildings cannot continue construction work when the outdoor temperature hits 50C.

Thankfully such temperatures aren't likely in the UK just yet, but what can you legally do if your workplace is getting into the high 20s or even 30C and your office is becoming baking?

There's a recommended minimum temperature for a workplace, which is 16°C or 13°C if employees are doing physical work, but things get a bit less clear when it comes to a maximum.

Unfortunately, there is no set maximum temperature clearly defined in the law in the UK - but you might still be able to leave work early, according to PGM Solicitors.

This is because employers are expected to have 'reasonable responsibility' to keep a workplace to within an acceptable working temperature for people's health.

The firm's spokesperson explains: "Many employees believe there is a maximum workplace temperature set by the law which, once reached in the summer, means they're entitled to be sent home from work. Unfortunately this is not the case - yet.

"The Trades Union Congress wants to make it illegal to keep people at work indoors if the temperature is above 30C and protection in place for people working outside or driving for a living too.

"The good news is that there are still rules that can let you leave an office that is too hot."

PGM goes on to quote the TUC, which says: "An employer must provide a working environment which is, as far as is reasonably practical, safe and without risks to health. In addition, employers have to assess risks and introduce any necessary prevention or control measures."

The Workplace (Health, Safety and Welfare) Regulations 1992 lay down particular requirements for most aspects of the working environment. Regulation 7 deals specifically with the temperature in indoor workplaces and states: "During working hours, the temperature in all workplaces inside buildings shall be reasonable. When defining reasonable, you need to take into consideration the nature of the workplace such as a bakery, a cold store, an office or a warehouse."

PGM continues: "There are six basic factors an employee should look at including air temperature, radiant temperature (i.e. the temperature radiating from warm objects), air velocity, humidity, and what clothing or insulation workers are expected to wear.

"The law also states that if 'a significant number of employees are complaining about thermal discomfort' then it's the employer's responsibility to carry out a risk assessment, and act on its results, adjusting the workplace temperatures:

• If your office is air-conditioned, the employer must assess things if 10 per cent of staff complain
• If your office is not air-conditioned, 15 per cent must complain
• In shops and warehouses 20 per cent of staff need to complain

The Health and Safety Executive says about the hot conditions: "A meaningful maximum figure cannot be given due to the high temperatures found in, for example, glass works or foundries.

"The Workplace (Health, Safety and Welfare) Regulations 1992 lay down particular requirements for most aspects of the working environment. Regulation 7 deals specifically with the temperature in indoor workplaces and states that:

"During working hours, the temperature in all workplaces inside buildings shall be reasonable.

"However, the application of the regulation depends on the nature of the workplace, such as a bakery, a cold store, an office, a warehouse."